


Enemies of the Heir, Beware

by FantasticNumberNine



Series: John Watson and the Chamber of Secrets [5]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: AU, Again, Crossover, Enemies of the Heir beware, Gen, Potterlock, The Chamber of Secrets has been opened, The boys talk, filch thinks they're guilty, holmsian style, jim is a jerk, lockhart is a ponce, snape would like to agree, the "f" word
Language: English
Status: Completed
Published: 2014-08-17
Updated: 2014-08-17
Packaged: 2018-02-13 13:43:00
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,562
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2152839
Author URL: https://archiveofourown.org/users/FantasticNumberNine/pseuds/FantasticNumberNine
Summary: <blockquote class="userstuff">
              <p>John, Greg, and Mycroft have just escaped the Deathday Party and are hoping to make it to the Halloween feast in time for dessert, but John starts hearing the voice in the walls again--and this time, the voice is aiming to kill.</p>
            </blockquote>





	Enemies of the Heir, Beware

**Author's Note:**

> *disclaimer*
> 
> So this is back. And deviating from CoS because I can. This is fan fiction.

John went to Nearly-Headless Nick's Deathday party because he'd promised he would. Mycroft came along because he thought it would be fascinating. Greg followed them because he was their friend. 

It wasn't a complete disaster--how Mycroft had gained the sobbing ire of Moaning Myrtle was mystery, one Greg was determined to solve on their way to pudding in the Great Hall.

"--But she haunts a _girls_ toilet, Myc!"

"How many times have I told you--"

"What were you doing in a _girls_ toilet?"

"--Mycroft, my name is _Mycroft_ \--"

"You'd think after the troll incident you'd want to avoid girls toilets--"

"--Not _Myc_ \--"

" _Rip... Tear... Kill..._ "

John froze ahead of them and Greg collided solidly into his back, sending them both tumbling to the stone floor. 

"What the hell--"

"Did you hear that?" 

John scrambled to his feet, Mycroft and Greg staring at him.

"John, what are you--"

"Shut up--it's that voice again--"

" _Sooooo hungry... For so long..._ "

"Listen!" 

" _... Kill... Time to kill..._ "

The voice was fainter now, John was certain it was moving upwards and he stared at the ceiling with a curiosity fueled by fear and excitement. How was it moving upwards, through stone?

"This way!" John shouted as he began to run, up stairs, and through the Entrance Hall and up the marble staircase to the first floor.

"John, what're we--"

"SHH!"

John closed his eyes, concentrating, and there was the voice again, above him.

" _... I smell blood... I SMELL BLOOD!_ "

"It's going to kill someone!" John breathed and, ignoring Greg and Mycroft's bewilderment, he took off again, up the next flight of stairs.

John raced around the second floor, Greg at his side and Mycroft panting behind them, not stopping until they hurtled around one final corner into a deserted passage.

"John, _what_ are we doing here?" Greg asked, bent over to catch his breath. "I couldn't hear anything..."

But it was Mycroft who pointed, gasping, down the corridor.

" _Look!_ "

John, Greg, and Mycroft approached the wall ahead slowly, squinting in the faint light of flaming torches at the huge words painted between two windows.

_THE CHAMBER OF SECRETS HAS BEEN OPENED.  
ENEMIES OF THE HEIR, BEWARE._

"What's... Eh... What's the thing... Hanging... Hanging underneath?" Asked Greg, a slight tremor in his voice,

The boys stepped closer, John nearly slipping in the puddle of water that spread across the floor and saved by Greg and Mycroft grabbing his arms. They realized what the thing was simultaneously and splashed backwards immediately.

For a few seconds, none of them moved, transfixed by Mrs. Norris hanging by her tail from one of the torch brackets, stiff as a board. Greg broke the silence.

"We should get out of here."

John gestured awkwardly, "Shouldn't we--" 

"No, trust me, we do _not_ want to found here."

Unfortunately, it was already too late to escape. The feast had ended, and students poured into the corridor from either side, loud and well-fed. Their noise ended abruptly as they saw John, Greg, and Mycroft standing alone in front of the morbid scene.

A lone voice drawled through the quiet.

"Enemies of the heir, beware?" Moriarty had slunk through the masses to stand in front of John, exaggerated shock painted on his pale face before morphing into a delighted grin, his eyes flicking briefly to Mycroft. "You'll be next, Mudbloods!"

John was more than a little disgruntled as he walked alongside Greg and Mycroft behind their professors to Lockhart's office--largely because they were headed to _Lockhart's_ office, but _his_ being accused of killing off the mangy cat when _Moriarty_ had been the one bandying offensive and derogatory words was also upsetting. 

"--Definitely a curse that killed her--probably the Transmogrification Torture. I've seen it used--"

John resisted the overwhelming urge to roll his eyes, glancing at Mycroft to see him gazing up at Lockhart with blind fascination. 

"--I remember something similar happening in Ouagadougou, a series of attacks, the full story is in my autobiography--"

Greg elbowed Mycroft sharply and he retaliated by stomping on Greg's foot.

"--I was able to provide the townsfolk with various amulets which cleared the matter up at once--"

John folded is arms and stared at the ceiling as the photographs and portraits on Lockhart's wall nodded in agreement as the actual Lockhart blathered on.

"She's not dead, Argus," Dumbledore said as he finished examining Mrs. Norris. "She has been petrified--"

"Ah! Yes, I thought so!" Lockhart interjected.

Dumbledore, and everyone else, ignored him. 

"But how, I cannot say..."

Filch shrieked, pointing an ugly finger at John, "Ask _him_!"

"No second-year could have done this, it would take Dark Magic of the most advanced--"

"He did it, he did it! You saw what he wrote on the wall! He--my office--he knows--he found--I'm-- _He knows I'm a Squib_!"

John had had enough, and now everyone (including the portraits) was staring at him.

"I never touched Mrs. Norris!" He said loudly, glaring at the Lockhart who'd left his curlers in. "And I've no idea what a Squib _is_."

"If I might speak, Headmaster," Snape's voice sounded from the shadows and John wondered if he ought to just fling himself off the astronomy tower now, nothing good would come from the greasy bat.

"Watson and his friends may have simply been in the wrong place at the wrong time," Snape sneered, obviously not believing such a thing possible. "But we do have a set of suspicious circumstances here. Why were they in the upstairs corridor at all? Why weren't they at the Halloween feast?"

John, Greg, and Mycroft launched into an explanation: the invitation from Nearly Headless Nick to attend his Deathday Party, how Mycroft thought it would be educational, and that there were hundreds of ghosts present and that--

"They can tell you we were there--"

Snape was unconvinced.

"But why not join the feast afterwards? Why go up to that corridor?"

"Because..." John began.

"Because we were tired, and we wanted to go to bed," Mycroft finished impatiently.

"Without any supper?" Snape pushed triumphantly. "I didn't think ghosts provided food fit for the living at their parties."

"We weren't hungry!" Greg exclaimed over the sound of his stomach rumbling.

In the end Dumbledore sent them to bed, despite Snape's glares and Filch's screeching. John remained silent as they walked up to Gryffindor Tower, with Greg and Mycroft glancing between him and each other.

"Do you think I should have told them? About the voice?"

They had nearly reached the portrait hole. Greg grabbed John by the shoulders, stopping his concentrated shuffle and Mycroft sighed dramatically. 

"John," Mycroft pinched the bridge of his nose, for all appearances a king amongst peasants. "John, in the wizarding world, as in the muggle world, hearing voices that no else can is a sign of madness."

"You think I'm mad, do you?" 

Greg shook him, "No, we don't. It's just... Weird, you know?"

"I didn't ask for this--"

"For god's sake, John, we _know_. You'd like to be painstakingly ordinary; I know I'd have preferred a quiet year too, but don't pretend you're not going to investigate the 'Chamber of Secrets' until we all wind up facing murderous monsters underneath the school again come May."

John and Greg stared at Mycroft like he'd grown a spare head and he glowered right back briefly before ducking his head to stare at his shoes.

"What... What was that?"

"I... I'm not brave... I've... I'm not..." Mycroft stuttered before exclaiming, "Don't either of you read?"

John raised his eyebrows, uncertain of just when Mycroft had stolen his insanity.

"The Chamber of Secrets!" Mycroft glared at them, throwing his hands up at their lack of response, before turning to Gryffindor Tower. "Granted, it's not like Binns teaches anything worth listening to, but honestly... It's basic Founder's mythology--potentially history if the Chamber is actually open now--"

John and Greg walked behind Mycroft as he led them through the common room and up to their dormitory, Greg leaning in to whisper to John:

"Did we break him so soon? There's still five years to go after this one..."

John coughed to cover a snort of laughter.

"--Says that Salazar Slytherin built himself a secret chamber deep within the school--"

John sat next to Greg on his bed as Mycroft paced between the beds.

"I'm not convinced that I'm the crazy one..." He whispered loudly.

Mycroft paused, narrowing his eyes at John.

"... Reportedly, Slytherin placed a monster only he could control inside the Chamber to rid the school of undesirables--those who, like myself, are muggleborn."

Greg rolled his eyes, "Slytherin's monster is a myth, Myc--" Mycroft opened his mouth, "-- _Croft_... It's not real."

"Perhaps. But you'll forgive me if I don't jump headfirst into this year's mystery."

"Mycroft," said John, "You're our friend. If we-- _when_ we start looking into this, we'll... We won't _endanger_ you."

Mycroft blinked. "Are we friends?"

"Yes, of course, you great pillock!"

Greg laughed, "You think we'd save just anyone from a rampaging troll, do you?"

"I... I do believe John would have saved Moriarty from the troll if he had had to," Mycroft smiled, mischief glimmering in his eyes.

The argument that followed descended into a pillow-throwing madness that had the boys soon forgetting about the writing on the wall and it's implications, and all of them slept soundly that night.

**Author's Note:**

> Isn't it super easy to imagine kid!Mycroft reading everything available at Flourish and Blotts about Hogwarts and its founders? It's actually very difficult writing a not-omniscient Mycroft...
> 
> This scene completely screwed with my chapter plans. So Sherlock will be in the next bit.
> 
> Cheers.


End file.
